Zig-zag folding system



Jan. 16,1968 TAKASHVI ABE ET AL 3,363,895

' ZIG-ZAG FOLDING S'YSTE'M Filed May 18, 1965 INVENTORS. .TAKASHI ABE Alf/RA SHINADA T nrronusrs.

United States Patent assignors Tokyo, Japan,

ABSTRACT OF THE DISCLOSURE A method of piling a web of material predisposed to fold in a zig-zag manner including the step of transversely vibrating the web above a refold zone.

This invention relates to a sheet folding system for high speed printers and the like which use a continuous supply of sheet material.

When using high speed printers through which continuous paper is fed, it is extremely important that the sheet be folded smoothly and without error, since the latter requires a material effort to correct.

In conventional systems a metal mesh or chain-like part is installed at the emergent end of the paper run (just prior to the point of collection) with sufficient flexibility to allow the natural fold resilience of the paper to dominate its transverse direction. Alternatively, a rather precisely timed auxiliary transverse force is imparted to the paper with a frequency of F cycles per second; where F equals V /L and V is the form advancing speed and L is the length between folds (i.e. length between perforations).

In the former case, however, the recovery force is not constant and depends upon the time the fold has spent on the roller (particularly where the direction of curvature is opposite the fold), and the weight of the paper itself. Hence a smooth operation is not always obtainable. Where an additional transverse force is imparted with the described frequency to perforated forms or prefolded forms it is completely dependent upon the advancing speed of the paper. While complicated transmission may be introduced to ensure coincidence of fold frequency and paper speed, an increase in the advance rate of the paper is accompanied by increasing air resistance to the transverse force and the fold may not follow the direction of the force.

Accordingly, it is the object of this invention to provide a method of folding paper or the like which is simple and yet avoids the disadvantages of conventional systems.

The above mentioned and other features and objects of this invention and the manner of attaining them will become more apparent and the invention itself will best be understood by reference to the following description of an embodiment of the invention taken in conjunction with the accompaying drawings wherein:

FIG. 1 illustrates schematically a printing machine employing the inventive concept; and

FIG. 2 is a partial sectional detail of the vibrating assembly in FIG. 1.

Turning noW to FIG. 1, there may be seen a line printer of the type conventionally coupled to a computer and operating at high speed. The paper 6 is fed by the traction or sprocket wheels 4 and 4 from its storage position 8 in the cabinet 1, through the printing mechanism 5 where the type faces are caused to strike against the paper backed by the drum 3. After emerging from the upper traction feed 4', the paper enters the flexible guide mesh 7 and via the vibratory guide 10 is stacked in pile 11.

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The guide 10 may be fixedly connected to the mesh 7 or, if desired, hingedly depending therefrom. In the latter case, the mesh may be replaced by a rigid structure, though a flexible one is preferred. Vibration is imparted to guide 10 in the direction of the arrows 12 by a source 9.

According to the invention, the form is vibrated at a constant frequency F greater than F (defined above). Consequently, since the frequency of the transverse force is greater than the fold frequency F a component of force is always available towards the pile center before the paper exhibits an attitude which would result in an error.

FIG. 2 illustrates a simple arrangement for producing the vibrations. A solenoid 13 fastened to a wall 14 of the printer by bracket 15 has an associated slug 16 secured to the guide 10. The slug is journaled in a bushing 19 to reduce friction, and has surrounding its exposed periphery a spring 18 for normally urging the slug to its most extended position. The solenoid winding is coupled via a series A.C. source to a pair of contacts 20, the closure of which depends upon an eccentric wheel 21. The speed of the wheel is such that it makes revolutions at the F rate. The wheel 21 may be directly or indirectly driven by the main printer motor. It will be apparent to those skilled in the art that many other arrangements could be employed for vibrating the guide. For example, an eccentric wheel such as that shown may directly drive the guide without a solenoid by employing a bell crank transmission.

While we have described above the principles of our invention in connection with specific apparatus, it is to be clearly understood that this description is made by way of example and not as a limitation to the scope of our invention as set forth in the objects thereof and in the accompanying claims. For example, the vibration need not be mechanically initiated, but air of electromagnetic force may be employed to effect the same result. Further, the material need not necessarily be paper, most continuous foldable sheet material may be used in the manner taught by the invention.

We claim:

1. The method of piling a continuous web of material predisposed to fold in a zig-zag manner wherein said web has fold lines regularly spaced therealong defining forms of a given length, comprising advancing said web at a given rate of speed, guiding said web downwardly along a substantially vertical path through a zone spaced above a substantially horizontal planar reception area, at said Zone vibrating said guided web in a direction transverse to said path at a frequency greater than said material advancing rate divided by said form length, and allowing said vibrated web to freely descend from said zone upon said reception area whereby said web of material is piled in zig-zag folds.

2. The invention claimed in claim 1 in which said material is paper.

3. The invention claimed in claim 2 in which the paper includes linear perforations spaced by the form folding length.

References Cited UNITED STATES PATENTS 2/ 1945 Sherman 27052.5 9/1959 Blain 270-6l 

